A banknote handling apparatus according to a related art includes, for example, a discriminating unit that discriminates denominations of banknotes that have been input, a holding unit that temporarily stores therein the banknotes discriminated by the discriminating unit, and a storage unit that stores therein banknotes sent from the holding unit. There is a banknote handling apparatus in which the discriminating unit, the holding unit, the storage unit, and a conveying mechanism that conveys the banknotes to each of these units are configured as a banknote handling module (hereinafter, also referred to as a mechanical module). There is also a banknote handling apparatus that includes such a banknote handling module includes another mechanical module that handles bank passbooks or cash cards.
In this type of the banknote handling apparatus, to simplify and improve efficiency of the configuration, electrical power is supplied to each of the mechanical modules from a power supply unit that is provided in the apparatus main body. Then, in the banknote handling apparatus, if maintenance, repair, or the like of each of the mechanical module is performed, after having disconnected the power supply unit in the banknote handling apparatus, maintenance, repair, or the like of a desired mechanical module is performed. Furthermore, there is also a known banknote handling apparatus having the configuration, in which a banknote unit and an application that performs banknote processing, are connected by using a USB cable.    Patent Literature 1: Japanese Laid-open Patent Publication No. 2011-186857
Incidentally, if maintenance or repair of one of the plurality of mechanical modules is performed, because the power supply unit in the apparatus main body is disconnected, the power supply of the other mechanical modules that do not need to be repaired or the like, is also disconnected, and the operation thereof is stopped. Thus, a backup operation of handling data in the banknote handling apparatus may sometimes be needed and it takes time to disconnect the power supply unit. Furthermore, if the power supply unit is turned on again after having installed the mechanical modules in the banknote handling apparatus, it also takes time to return to the state in which the entire banknote handling apparatus can perform a handling process. As a countermeasure against this issue, it is preferable that the banknote handling apparatus is configured such that, by connecting the power supply unit of the banknote handling apparatus to each of the mechanical modules via the respective power supply cables, the power supply can be individually disconnected from the power supply unit for each mechanical module without disconnecting the power supply unit in the banknote handling apparatus.
However, in the mechanical modules described above, a large amount of current is needed to drive the conveying mechanism that conveys the banknotes, bank passbooks, or the like. Thus, after the mechanical modules are disconnected from the power supply unit, inrush currents may possibly be generated when electrical power is supplied from the power supply unit to the mechanical modules. If an inrush current to a mechanical module is flowed when the power supply cable is connected to a connector of the mechanical module, this may possibly result in degradation of the connector or malfunction of the mechanical module.
Accordingly, the present invention has been conceived in light of the circumstances described above, and an object thereof is to provide a paper sheet handling apparatus and a method for controlling the paper sheet handling apparatus that can prevent degradation or malfunction of paper sheet handling modules due to an inrush current from being incurred and that can insert and remove the power supply cable for paper sheet handling module without disconnecting the power supply unit.